Trimalleolar Equivalent Fracture

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July 20, 2015
Edward Smith

trimalleolar equivalent fracture

The ankle joint is a rather complex joint which is actually two joints in one.  The ankle joint proper is made by ligamentous connections which connect the distal tibia and distal fibula to the talus near the patient’s heel.  Another joint is called the syndesmotic joint and is the connection between the tibia and fibula.  A strong ligament is located between the two bones so that the lower leg can have some stability.

Complex ankle fractures can happen after a motor vehicle accident or serious fall.  These include bimalleolar and trimalleolar fractures of the ankle.

Bimalleolar Fracture of the Ankle

 A bimalleolar fracture is on in which the distal fibula is fractured along with one of the bony prominences at the distal end of the tibia.  This “double fracture” is often associated with ligamentous injury and instability of the fracture, especially if the bones are displaced.  The fractures occur at the bump on the outer aspect of your ankle as well as the bump on the inside of the ankle.

Bimalleolar fractures are almost always unstable and require open reduction and internal fixation (also known as ORIF).  This basically means that the surgeon must make an incision in the ankle and use plates, screws and pins to align the bony fragments of the ankle so that it can heal in the proper position.

Bimalleolar fractures are usually easily visualized using plain film x-ray.  It shows the two fractures and any dislocation of the joint that happens to be present.  When a surgical plan is made, the surgeon will repair the two fractures and will place the patient in a lower leg cast for about six weeks.  Follow up x-rays are recommended to make sure that the bones are healing in the proper position.  In general, the “hardware” put into an ankle after a bimalleolar fracture is kept in place for the life of the individual unless there is some complication so that the hardware must be removed.

Most people can have no or minimal weight bearing after surgery to correct the bimalleolar fracture.  Crutches or wheelchair is used to keep pressure off the joint as it heals.  Complications of ankle surgery to repair a bimalleolar fracture include excessive bleeding, infection in the surgical wound, failure to heal, arthritis in the ankle or stiffness in the ankle that persists after the cast is removed.

There is a type of fracture known as the “bimalleolar equivalent fracture”.  What this means is that one of the malleoli are fractured and the ligaments on the inner aspect of the ankle are disrupted.  The lateral malleolus and medial ligaments are both injured, making the ankle fracture unstable.  Sometimes, stress must be placed on the ankle to see if the medial ligaments have become disrupted.  The treatment is surgical repair of the ligaments and the distal fibular fracture.

Nonsurgical repair of a bimalleolar fracture is only done in cases where the victim has a significant health problem and cannot tolerate surgery or if the patient is not ambulatory in the first place.  Surgery is only indicated in those people who plan to return to an ambulatory status.  If no surgical treatment is planned, the ankle is placed in a dorsal splint for comfort and to keep the ankle immobilized.  Once the swelling of the ankle subsides, a cast can be placed so that the ankle can heal over a course of 6 weeks.  During that 6 week period of time, no weight-bearing is allowed on the affected ankle.  Braces can later be used to protect the ankle from pain and further injury after the ankle has healed.

Trimalleolar Fracture of the Ankle

 In a trimalleolar fracture of the ankle, there are three points of fracture.  One is the lateral malleolus, which is essentially a distal fibular fracture.  The medial malleolus is also fractured as is the distal back part of the tibia, often referred to as the posterior malleolus.  Dislocation of the ankle and disruption of major ligaments of the ankle are also included in this type of fracture.  The fractured bony parts are those that connect the tibia and fibula to the talus.  The term, trimalleolar is a bit of a misnomer as there really are only two major prominences on the ankle, the medial and lateral malleolus.  Nevertheless, the tibia is fractured in two places and the ankle joint is unstable.

Treatment of a trimalleolar fracture is almost always surgical using open reduction and internal fixation.  The bony fragments are held together with plates and screws in proper alignment so that the ankle fractures can heal over a six week period of time.  No weight-bearing is allowed on a trimalleolar fracture until the person reaches the six week mark (or longer if the patient is older or diabetic).  Nonsurgical repair of a trimalleolar fracture is recommended if the patient cannot tolerate surgery due to health problems or if they are already non-ambulatory.  In such cases, the ankle is allowed to rest until the swelling goes down and a cast is applied for at least three weeks.

Complications of Bimalleolar and Trimalleolar Fractures

 Because these fractures are intra-articular (within the joint itself), there is a high risk of later arthritic changes and chronic pain in the affected ankle.  Arthritis can begin as soon as the patient gets out of their cast or can develop over time as the normally smooth articular surface is no longer smooth.  It is not uncommon for a person with a history of either of these two fractures to develop degenerative arthritis that lasts a life time.

In order to reduce complications and improve functionality, physical therapy is recommended for all patients who have sustained these types of fractures to the ankle.  Physical therapy is designed to strengthen the ankle as much as possible and to provide modalities to control the arthritic pain.  Many patients will require ongoing doses of NSAIDs like ibuprofen or naproxen, or COX-2 inhibitors like Celebrex®, which can reduce the pain and inflammation of an arthritic joint.

Some patients require long term bracing or soft ankle splint to help reduce pain and increase ambulation until the ankle becomes stronger and less painful over time.

Bimalleolar and Trimalleolar Fractures often result from trauma on an automobile or motor vehicle accident.

Ed Smith, is a Injury attorney in Sacramento very experienced in these fractures and their consequences. His firm is a member of the Million Dollar Advcates Forum and is rated highly on Yelp, Avvo and Google. His Motor Vehicle website, is the most comprehensive auto accident website in California.

Please call Ed anytime for free, friendly advice at 916-921-6400 in Sacramento or 800-404-5400 Elsewhere.